Herbicides of the carbamate, thiolcarbamate, chloroacetanilide and dichloroacetanilide type are widely used in the everyday practice of agriculture. They are for example disclosed in the U.S. Pat. Nos. 2,863,752; 2,864,683; 3,442,945; 2,913,327; 2,695,225; 2,906,614; 3,330,643; 3,330,821; 3,330,642; 3,198,786; 3,573,031 and 3,175,897.
As previously stated, herbicides are widely used in agriculture. The herbicidally active chloroacetanilide and thiolcarbamate derivatives, however, injure the cultivated plants as well, they are therefore often combined with various antidotes. Certain antidotes, which reduce the phytotoxic effect of thiolcarbamate herbicides on agricultural plants show a protecting effect in combination with chloroacetanilide herbicides, too, in various cultures, e.g. maize [J. Robert, C. Levitt, D. Penner: J. Agr. Food. Chem. 27(3), 533-536 (1979)]. Such antidotes are for example disclosed in the Belgian Patent Specifications Nos. 782,120 and 806,038, in the U.S. Pat. Nos. 3,893,838 and 3,931,313 and in the Hungarian Patent Specifications Nos. 165,736, 176,784 and 168,977.
In addition to their toxic effect on the cultivated plants, another problem in connection with these herbicidally active ingredients is that the duration of their effect is not satisfactory.
As it is well known, immediately after spraying the concentration of the above-mentioned herbicides and antidotes is very high in the upper layer of the soil, but later on it decreases rapidly. This may lead to an invasion of weeds and, as a result, to the injury of cultivated plants. The reasons for this phenomena are discussed by Kaufman, D. D.-Kearney, P. C. (Appl. Microbiol. 13, 443-446 (1965)) and Fox, J. L. (Science, 225, 1029-1031 (1983)). It is concluded that especially the active ingredients containing mn--C.dbd.(O) groups are rapidly decomposed by the microbes present in the soil.